Chapter 10 - Disease and Immunity

Question 1

Define pathogen

Answer 1

a microorganism that causes disease

Question 2

Name 3 examples of disease that viruses cause

Answer 2

• influenza
• common cold
• poliomyelitis
• measles
• AIDS / HIV
• covid - 19

Question 3

Name 3 examples of disease that bacteria cause

Answer 3

• cholera
• syphilis
• whooping cough
• tuberculosis
• tetanus

Question 4

Name 1 example of a disease that protoctists cause

Answer 4

• malaria
• amoebic dysentery

Question 5

Name 1 example of a disease that fungi cause

Answer 5

• athlete’s foot
• ringworm

Question 6

Define host

Answer 6

the organism that the pathogen lives in and reproduces within

Question 7

Define infection

Answer 7

the entry of a pathogen into the body

Question 8

Where can infections enter?

Answer 8

• air
• cuts
• water

Question 9

Define tranmission

Answer 9

the movement of a pathogen from on host to another

Question 10

Define transmissible disease

Answer 10

diseases caused by pathogens that can be passed from one host to another

Question 11

In what 2 ways do pathogens damage our cells when inside the body?

Answer 11

• using up resources
• producing toxins which cause symptoms

Question 12

What are the 2 characteristics of toxins caused by pathogens?

Answer 12

• waste products
• some can be highly poisonous

Question 13

What are the 2 ways in which diseases can be transferred?

Answer 13

direct and indirect contact

Question 14

Name an example of direct transfer of a disease

Answer 14

pass through blood

Question 15

Name 3 examples of indirect transfer of a disease

Answer 15

• breathing in droplets (coughing, sneezing)
• touching a surface an infected person touched (e.g. food poisoning)
• eating or drinking from the same source if an infected person
• contact with animals carrying pathogens

Question 16

What happens in the skin is broken?

Answer 16

a blood clot forms to seal wound and prevent pathogens from getting in

Question 17

How does the stomach kill bacteria in food?

Answer 17

using HCl

Question 18

How does the nose prevent pathogens from entering the body?

Answer 18

nose hairs which filter air

Question 19

What happens when we smell or taste something bad?

Answer 19

our body doesn’t want it

Question 20

What does the mucus in airways do to prevent pathogens from entering?

Answer 20

traps bacteria and swallows it instead of going to lungs

Question 21

In what ways can we ensure safe and clean water?

Answer 21

filter water and treated with chlorine

Question 22

Can water contain pathogens?

Answer 22

yes

Question 23

We use what we know about bacteria to ensure they stay away from food and drinks. What do we do to ensure this? (4)

Answer 23

• keep microbes away
• keep animals away
• keep food at low or high temperatures
• keep raw meat away

Question 24

What can happen if oil on skin builds up?

Answer 24

it can collect dirt and microbes

Question 25

What substances that can accumulate on the skin can be breeding ground for bacteria?

Answer 25

- sweat - dirt - oil

Question 26

How can we prevent teeth decay and keep microbes away from mouth?

Answer 26

brush teeth

Question 27

Do animals search for food in waste?

Answer 27

yes

Question 28

Why should waste be collected regularly?

Answer 28

- avoid infection - avoid pollution

Question 29

What can trash be rotted by?

Answer 29

decomposers

Question 30

What gas do bacteria produce?

Answer 30

methane gas that is highly flammable

Question 31

Sewage =

Answer 31

waste liquid

Question 32

Name 3 examples of where sewage comes from

Answer 32

- bathrooms - kitchens - factories

Question 33

Name 3 examples of substances that can be in sewage

Answer 33

- urine - oils - toilet paper - detergents

Question 34

How is cholera spread?

Answer 34

through water / food that has been contaminated by the faeces of an infected person

Question 35

Name a place where cholera can spread quickly

Answer 35

refugee camps

Question 36

Explain how cholera infects the body

Answer 36

1. cholera bacteria are ingested and multiplied 2. bacteria attach to alimentary canal walls 3. bacteria release toxins 4. toxins cause Cl⁻ ions to be released 5. this causes water to move into lumen by osmosis 6. now there is a lot of water in the canal. blood contains too little Cl⁻ ions and water

Question 37

How can cholera be fatal?

Answer 37

dehydration

Question 38

How can a person recover from cholera?

Answer 38

if enough fluid is replaced

Question 40

Define antibodies

Answer 40

molecules secreted by white blood cells (lymphocytes only) which bind to pathogens and destroy them

Question 41

What are antibodies?

Answer 41

proteins that have a specific shape which is complementary to an antigen

Question 42

Define antigen

Answer 42

a chemical that is recognised by the body as being 'foreign' and stimulates the production of antibodies

Question 43

Where are antigens usually located on a pathogen?

Answer 43

on the outside

Question 44

How are antibodies shaped?

Answer 44

specifically to fit the shape of the specific antigen

Question 45

How do antibodies eliminate pathogens?

Answer 45

by attaching to the antigens, forming clumps and 'feeing' those clumps to a lymphocyte.

Question 46

Define immune response

Answer 46

the reaction of the body to the presence of an antigen

Question 47

Define memory cells

Answer 47

long-lived cells produced by the division of lymphocytes that have contacted an antigen. they respond quickly to future contact with the same antigen

Question 48

This is how antibodies react when exposed to contaminated food. What does the graph look like after eating the same contaminated food again?

Answer 48

Question 49

For how long do memory cells stay in the blood after an immune response?

Answer 49

a long time

Question 50

Define vaccination

Answer 50

a **harmless** preparation of dead or inactivated pathogens that is injected into the body to start the immune response

Question 51

What 3 substances can vaccines be made of?

Answer 51

- dead cells from disease - pieces of cells from disease - cells made from a similar disease

Question 52

★ What are vaccines never made of and why?

Answer 52

never from inside of cells because antigens is what stimulates immune system

Question 53

Why do some diseases require 2 vaccinations?

Answer 53

for long lasting immunes

Question 54

What are the 2 vaccines called and what is their purpose?

Answer 54

First dose: partial protection - stimulates production of some memory cells Second dose: "booster" - stimulates production of even more memory cells

Question 55

How can someone have active immunity?

Answer 55

if their body made its own antibodies and memory cells

Question 56

How is active immunity developed?

Answer 56

- having disease and recovering - being vaccinated

Question 57

Can active immunity last a lifetime?

Answer 57

yes

Question 58

How can someone have passive immunity?

Answer 58

if they have been given ready-made antibodies

Question 59

How can passive immunity be developed?

Answer 59

- injection - babies get this through breast feeding

Question 60

What does a human have to do if they get bitten by an animal with rabies?

Answer 60

have to get an injection or else it could be fatal within 48 hours

Question 61

When can the milk passed from mother to child help?

Answer 61

during the first few months of life

Question 62

Why does passive immunity last for a short amount of time?

Answer 62

because it is broken down (no memory cells are created)

Question 63

What can polio do to children?

Answer 63

leave them partially paralyzed

Question 64

How can polio be spread?

Answer 64

through water

Question 65

Why is herd vaccinating useful?

Answer 65

* vaccinating children does not only protect the chldren vaccinated but also those around them * there are fewer places for the pathogen to replicate